Add CKEditor-TeXZilla plugin

Link to CKEditor-TeXZilla: https://github.com/r-gaia-cs/CKEditor-TeXZilla

For this commit it was used c4e484c7f9fd71f5f313892a3da2919ee2b14722
Remove a few legacy CSS files, move wiki editor CSS to stylus
Revert cced5a201be5348f1f32cbbdaa61e922cf4b2bdb

Well, it turns out 2f62c0ceee7b2745276082b62c111fd57d3d174e did not
cause the bug after all. I still have no idea why reverting it fixed the
problem on stage, but it seems likely that I arrived at a false positive
in my rush to test and deploy a fix.

And with that, I humbly submit a pull request to revert a revert that
did not cause a problem. //developershame
Update based on version 1.0
Merge pull request #2060 from openjck/revert-revert-ga-outbound

Revert cced5a201be5348f1f32cbbdaa61e922cf4b2bdb
Revert "Issue #1964: DB fields for generated content - quick links, zone nav, and body HTML"

This reverts commit 59557f71f8f8ca166fd80dc26db34c3f83ae2115.
Merge pull request #2063 from groovecoder/revert-content-fields

Revert "Issue #1964: DB fields for generated content - quick links, zone...
Hard restart for httpd in chief_deploy.py
Merge pull request #2065 from lmorchard/hard-restart-for-apache

Hard restart for httpd in chief_deploy.py
Merge pull request #2038 from r-gaia-cs/TeXZilla

Add basic math editing features
disable google-analytics.js with  'a' selector

exclude noisy javascript: links from tracking
Merge pull request #2066 from groovecoder/outbound-links-javascript

exclude noisy javascript: links from tracking
Bug 951775 - Add a list of pages with errors to the wiki
Issue #2062: Reduce DB queries involved in annotating links to existing or new wiki pages
Utilize syntethetic events instead of triggering common events
Merge pull request #2057 from darkwing/remove-legacy-css

Remove a few legacy CSS files, move wiki editor CSS to stylus
Merge pull request #2067 from darkwing/synthetic-accordion-events

Utilize syntethetic events instead of triggering common events
Merge pull request #2068 from lmorchard/linkannotation-queries

Issue #2062: Reduce DB queries involved in annotating links to existing or new wiki pages
Put advanced profile features behind gear submenu

My hope was to A/B test this change with Optimizely, but we are
currently unable to run tests on page elements that only logged-in users
see.

When we made a similar change to article pages (moving the history
feature behind a gear icon) the edit button saw a statistically
significant increase in click rate, so we can be moderately confident
that the same thing will happen here.
Merge pull request #2028 from openjck/profile-advanced-menu

Put advanced profile features behind gear submenu